#pragma once

#include <QHBoxLayout>
#include <QScrollArea>
#include <QTabWidget>
#include <QWidget>

#include <cassert>
#include <type_traits>

namespace chatterino {

template <class T>
class LayoutCreator
{
public:
    LayoutCreator(T *_item)
        : item_(_item)
    {
    }

    T *operator->()
    {
        return this->item_;
    }

    T &operator*()
    {
        return *this->item_;
    }

    T *getElement()
    {
        return this->item_;
    }

    template <typename T2>
    LayoutCreator<T2> append(T2 *_item)
    {
        this->addItem(this->getOrCreateLayout(), _item);

        return LayoutCreator<T2>(_item);
    }

    template <typename T2, typename... Args>
    LayoutCreator<T2> emplace(Args &&... args)
    {
        T2 *t = new T2(std::forward<Args>(args)...);

        this->addItem(this->getOrCreateLayout(), t);

        return LayoutCreator<T2>(t);
    }

    template <typename Q = T,
              typename std::enable_if<std::is_base_of<QScrollArea, Q>::value,
                                      int>::type = 0>
    LayoutCreator<QWidget> emplaceScrollAreaWidget()
    {
        QWidget *widget = new QWidget;
        this->item_->setWidget(widget);
        return LayoutCreator<QWidget>(widget);
    }

    template <typename T2, typename Q = T,
              typename std::enable_if<std::is_base_of<QWidget, Q>::value,
                                      int>::type = 0,
              typename std::enable_if<std::is_base_of<QLayout, T2>::value,
                                      int>::type = 0>
    LayoutCreator<T2> setLayoutType()
    {
        T2 *layout = new T2;

        this->item_->setLayout(layout);

        return LayoutCreator<T2>(layout);
    }

    LayoutCreator<T> assign(T **ptr)
    {
        *ptr = this->item_;

        return *this;
    }

    template <typename Q = T,
              typename std::enable_if<std::is_base_of<QLayout, Q>::value,
                                      int>::type = 0>
    LayoutCreator<T> withoutMargin()
    {
        this->item_->setContentsMargins(0, 0, 0, 0);

        return *this;
    }

    LayoutCreator<T> withoutSpacing()
    {
        this->item_->setSpacing(0);

        return *this;
    }

    template <typename Q = T,
              typename std::enable_if<std::is_base_of<QWidget, Q>::value,
                                      int>::type = 0>
    LayoutCreator<T> hidden()
    {
        this->item_->setVisible(false);

        return *this;
    }

    template <typename Q = T, typename T2,
              typename std::enable_if<std::is_same<QTabWidget, Q>::value,
                                      int>::type = 0>
    LayoutCreator<T2> appendTab(T2 *item, const QString &title)
    {
        static_assert(std::is_base_of<QLayout, T2>::value,
                      "needs to be QLayout");

        QWidget *widget = new QWidget;
        widget->setLayout(item);

        this->item_->addTab(widget, title);

        return LayoutCreator<T2>(item);
    }

private:
    T *item_;

    template <typename T2,
              typename std::enable_if<std::is_base_of<QWidget, T2>::value,
                                      int>::type = 0>
    void addItem(QLayout *layout, T2 *item)
    {
        layout->addWidget(item);
    }

    template <typename T2,
              typename std::enable_if<std::is_base_of<QLayout, T2>::value,
                                      int>::type = 0>
    void addItem(QLayout *layout, T2 *item)
    {
        QWidget *widget = new QWidget();
        widget->setLayout(item);
        layout->addWidget(widget);
    }

    template <typename Q = T,
              typename std::enable_if<std::is_base_of<QLayout, Q>::value,
                                      int>::type = 0>
    QLayout *getOrCreateLayout()
    {
        return this->item_;
    }

    template <typename Q = T,
              typename std::enable_if<std::is_base_of<QWidget, Q>::value,
                                      int>::type = 0>
    QLayout *getOrCreateLayout()
    {
        if (!this->item_->layout())
        {
            this->item_->setLayout(new QHBoxLayout());
        }

        return this->item_->layout();
    }
};

}  // namespace chatterino